The disclosed embodiments of the present invention relate to data management, and more particularly, to a method for managing an external portable storage device (e.g., a memory card) and a related machine readable medium.
An external portable storage device such as a secure digital (SD) memory card may be used by an electronic device for data storage. For example, the user may use an SD memory card on a tablet for storing application data and user data. If an operating system (e.g., Android) of the tablet supports a “multi-user” feature, an electronic device therefore can be used by more than one user, where users of the same electronic device are independent of each other. For one example, two users may use the same application that stores some of its data on the same SD memory card. For another example, one user may move an SD memory card from one electronic device to another electronic device having a different multi-user configuration.
However, adding the complexity of multiple users to something as portable as an SD memory card would undoubtedly create some problems. In a conventional design, each user is required to have his/her own private space with encryption on an SD memory card. But this behavior conflicts with the SD memory card's advantage—portability. That is, when any data in an SD memory card of a tablet platform is encrypted to meet the privacy requirements, the SD memory card's portability will lose due to the fact that encrypted data of the SD memory card cannot be easily shared on different tablet platforms and shared between different users. Besides, encryption will cause low access performance of the SD memory card.
Thus, there is a need for an innovative method for managing data stored in an external portable storage device (e.g., a memory card) to balance many factors such as privacy, portability and performance.